Microchip Technology MCP1603T-330I/MC

Overview

MCP1603T-330I/MC from Microchip Technology is a fixed-output 3.3V, 500 mA synchronous buck regulator optimized for single-cell Li-Ion and USB-powered portable devices. It operates from 2.7V–5.5V input, delivers >90% typical efficiency at full load, features 2.0 MHz PWM switching, integrated P/N-channel MOSFETs, and includes UVLO, overtemperature, and cycle-by-cycle overcurrent protection.

For engineers reviewing the MCP1603T-330I/MC datasheet, MCP1603T-330I/MC pinout, MCP1603T-330I/MC application, or MCP1603T-330I/MC equivalent, this device serves as a compact, low-quiescent-current DC/DC solution requiring only three external components (4.7 µF C_IN, 4.7 µF C_OUT, 4.7 µH inductor) for full operation in space-constrained battery-powered systems.

Technical Context

The MCP1603T-330I/MC is a PWM-only variant (MCP1603B family), disabling automatic PFM mode transition to eliminate low-frequency output ripple-critical for noise-sensitive analog or RF subsystems. It maintains constant 2.0 MHz switching across all loads, with a minimum required load for regulation dependent on VIN–VOUT headroom.

Its internal compensation, 0.8V reference feedback, and 860 mA peak current limit enable stable regulation without external loop components. Thermal shutdown activates at +150°C (10°C hysteresis), and undervoltage lockout engages below 2.28V (140 mV hysteresis), ensuring robust start-up and fault recovery in variable-input battery systems.

Key Specifications

Pinout & Package

Package: 5-Lead TSOT-23 (MCP1603/MCP1603B variant), footprint-optimized for ultra-compact PCB layouts.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar synchronous buck regulator applications.

Compared with TPS62231DRYR and ADP2303ARDZ-3.3-R7, the MCP1603T-330I/MC uniquely balances 500 mA capability, 2.0 MHz operation, and TSOT-23 size-making it optimal for cost- and space-constrained consumer portables where 3.3V stability and moderate efficiency are primary selection criteria.

Availability

MCP1603T-330I/MC is available at Aetrix Electronics and suitable for USB-powered peripherals, portable medical sensors, digital cameras, Bluetooth headsets, and Li-Ion battery-powered embedded systems requiring stable component supply and rapid prototyping support.

Supply support for MCP1603T-330I/MC includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Microchip Technology Inc. is a leading provider of microcontroller, mixed-signal, analog, and Flash-IP solutions, serving automotive, industrial, consumer, and communications markets with high-reliability silicon and development tools.

The MCP1603/B/L product line delivers highly integrated, low-footprint DC/DC buck regulators targeting portable battery-powered applications where efficiency, size, and ease of implementation are critical design constraints.

FAQ

What is the minimum load requirement for stable regulation of the MCP1603T-330I/MC?

The MCP1603T-330I/MC (as an MCP1603B-family part) requires a minimum load to maintain regulation under light-load conditions due to its PWM-only operation. Per Figure 2-15 in DS22042B, the minimum load depends on input-to-output voltage differential-for example, at VIN = 3.6V and VOUT = 3.3V, regulation is maintained down to ~5 mA. Below this, output voltage may rise above 3.3V. This behavior is inherent to fixed-frequency PWM architecture and must be accounted for in low-power sleep states.

Does the MCP1603T-330I/MC require external compensation components?

No, the MCP1603T-330I/MC is internally compensated. Its control loop is factory-tuned for stability with standard 4.7 µF input/output capacitors and a 4.7 µH inductor. No external RC network is needed-even for the fixed 3.3V output configuration-reducing design complexity and PCB area. This integration is confirmed in Section 4.1 and Table 3-1 of the official datasheet DS22042B.

Can the MCP1603T-330I/MC operate from a 2.7V input while delivering 500 mA at 3.3V?

No-operation at 2.7V input is not feasible for 3.3V output because VIN must exceed VOUT plus headroom (typically ≥0.4V for 500 mA). The datasheet specifies a minimum input of 2.7V only for lower output voltages (e.g., 1.2V–2.5V). For 3.3V output, practical minimum VIN is ~3.6V to sustain full load. At 2.7V, the MCP1603T-330I/MC will enter dropout or shut down via UVLO (2.28V threshold), as confirmed in Note 1 and Figure 2-15 of DS22042B.

How does the shutdown current specification of the MCP1603T-330I/MC compare to similar buck regulators?

The MCP1603T-330I/MC achieves 0.1 µA typical shutdown current (max 1 µA), matching industry-leading ultra-low-power regulators like the TPS6223x series. This value is measured with SHDN pulled to GND and VIN = 5.5V, and is validated across temperature (–40°C to +85°C). Such sub-µA shutdown enables multi-year battery life in always-on sensor nodes-critical for IoT edge devices where quiescent power dominates total energy budget.

Is the TSOT-23 package of the MCP1603T-330I/MC RoHS-compliant and lead-free?

Yes, the MCP1603T-330I/MC in TSOT-23 packaging is RoHS-compliant and lead-free, per Microchip's official product change notification (PCN) and material declaration. The "I" suffix in the part number denotes industrial temperature grade (–40°C to +85°C), and the "/MC" suffix confirms tape-and-reel packaging compliant with J-STD-020 moisture sensitivity level 1. Full compliance documentation is available in Microchip's Quality & Reliability portal under document #QG-001-102.